Improvement in expansion-drills



2 Sheets--Sheet 2.

M. C. BULLUGK. Expansion Drills.

Patented July 20, l875.

w 6 w 7U W,

MILAN C. BULLOCK, OF NEW YORK, N. Y.

IMPROVEMENT IN EXPANSION-DRILL'S.

Speciication forming part of Letters Patent No. 165,787, dated July 20, 1875 application filed November 28, 1874.

provement in drills or bits for perforating rocks for blasting; and the invention consists in a bit or drill for boring holes of unequal diameters in rocks, &c., in which the enlarging or expansion bits are hung in the bit-stock, and held in position by two conesf that are vertically adjustable. It further con? sists in constructing the drill-rod and stem of the adj Listing-screw hollow, and providing the cones, for expanding and holding the bits,f with central openings, so as to furnish a conduit for supplying Water to the drilling-sur faces, substantially in the manner hereinafter particularly described.

The invention relates more particularly to rock bits or drills, the cuttingsurfaces of which are composed of diamonds. The desirability of increasing the diameter of the drill-holes at certain places or intervals will be apparent-as, lor instance, when, after driving a hole of the ordinary diameter through a comparatively soft rock, an underlying stratum of harder rock is encountered. In such a case a hole of larger diameter, admitting a greater charge of powder, will be found very eiicacious. There are many other occasions when an adjustable expanding bit may be used to advantage. To derive these ad-A vantages I construct an adjustable expanding bit, as recited in the following description` and accompanying drawings, wherein- Figure l is a vertical section of my drill` with feed or adjusting-screw removed, showing expanding bits. Fig. 2 is a vertical section with the feed or adjusting screw in position, and showing the manner of supplying water to the cutting-surfaces. Fig. 3 is a cross-section taken in the line x a: of Fig. 2. Fig. 4 is a side elevation with expanding bits retracted; Fig. 5, a side elevation with bits expanded. Fig. 6 is a pla-n view of drill with bits expanded, and Fig. 7 a plan view of bits retracted.

Similar letters of reference indicate like parts in the several figures.

A represents the lower section of my drill. This section is cylindrical, and, for about three-fourths of its distance, it is hollow, with a screw-thread formed in a portion of ,this hollow interior, and with a shoulder, a, also formed therein. The remaining fourth of the length of this section issolid, and the under surface or bottom thereof is concave or of any suitable form. This concave lower surface may be tted with diamonds b, or other suitable cutting-points, as shown in Fig. l. This concave surface is also perforated with a series of holes, c. Firmly secured to the upper end of the section A, by screw-threads or otherwise, is a section, B. If it is intended that this section should be secured to the section A. by screw-threads, the lower end of this section B will have formed upon it screw-threads that shall correspond with the screw-threads in the section A. For this purpose the lower part of the section B, with the screw-'threads thereon, is made of somewhat less diameter than the other part of the same, so that when the two sections are screwed together, the two sections will come together with a tight joint and with smooth and uniform surfaces. Into the section B are formed two or more slots, d. These slots are preferably at right angles to each other, and are cut entirely through the sides ofthe section. Fitting into these slots are wings C. These wings are secured near their lower ends to the sides of the section B by pins e, and fitted within the interior of the section B (which is hollow) are two cones,D and E. These cones are arranged within the section B, so that the apex of each cone will point toward the apex of the other one, and they are connected together by a hollow stern, f, in such manner that the cone D will be above the pins c, that secure the wings in position, and the cone E will be below the inner ends of the wings C. These cones are constructed so as to slide readily within the interior of thel section B, and the upper one, D, of these cones has formed in its upper surface a recess with screw-threads cut into it, and into the upper end of the cone respond with the screw-threads cut in the-recess formed in the upper surface of the cone' D, into which it is screwed and thus secured. Through the sides of the tube G are perforations h., and into the outer surface of said tube are affixed keys or fins j, these iins entering into one of the channels @l when the tubular stem is within the coupling. The upper end of the tubular stem G is formed with a rounded head, k, which is received into the lower end of a small coupling, Z, abutting against a wooden bearing, m, the under surface of which snugly fits the rounded head of the tube G, in which position it is retainedzby two pins, n, which pass .through the small coupling l, and under lthe shoulder of the rounded head 7c, thus forming a ball-andsocket joint.

Extending upward from the coupling l isla stem, 0, the lower half of which is provided with a screw-thread. The tubular stem G is inserted through the coupling F, and its lower end is screwed into the cone D, before described; and when this tubular stem is in this position the under surface of the small coupling rests upon the surface of the shoulder:

formed by the counter-bore of the vinterior of the coupling F. Screw-threads'being lformed on the -upper portion of this last-mentioned coupling, a section, H, is screwed thereon.

end protrudes through the top of vthe section H. with screwthreads.

lstein o passes, and parallel with this opening, and opening into thesame, are two channels, r r.

the nut. The central opening or hole 'has screw-threads formed in it, into ywhich work foot of the drill or bit are well supplied with the threads on the stem o.

The section vH being screwed or otherwise secured to the upper end of the coupling F, the nut being placed in it, as before described, and the stem o passing up through said nut, a jam-nut, J, is screwed upon the projecting part 19 of the-nut I, holding the nut securely in position, and onto such portion of lthe projecting partvof the nut lI that projects above the jam-nutJ is screwed or otherwise secured a cap, K. This cap is in the form of a hollow cylinder, and has fitted near its upper end a The part p, that so protrudes,is providedV The nut I has drilled] throughit acen tral opening, through'which ther These channels extend entirely through Into pipe, L, and into its upper end is formed a packing-box, M, and to the end of that portion of the stem o which projects beyond the packing-box is fitted a crank, N.

Having now described the construction of my adjustable expanding drill, its operation is as follows: Being placed in position, it is caused to revolve. The diamonds or other cutting appliances, which are secured to the concave surface of its lower end, speedily cut the rock, so that as the drill is fed downward the ordinary drill-hole is formed. When this hole has-been driven as farfas is thought desirable the stem o is turned by means of the crank N, which causes it to freely turn within the nut, the stem freely revolving by reason of the balland-socket joint before named, and as the screw is thus turned the tubular stemG is forced-downward, and the cones D and E are also forced downward. The conical surface of the cone D, coming in contact with the inner edges of the wings G, forces them outward from the sides of the section B, so that as the drill Jrevolves these wings (their outer edges being armed with diamonds) will at once commence to enlarge the diameter of the original drill -hole, which will thereafter be continued ofthe enlarged diameter until the wings C are withdrawn'within the section B, when the original diameter of the drill-hole will be continued by the diamonds on the lower concave surface of the drill, and so on. If desired, the drill-hole may be lmade in sections of alternate openings having greater and less'diameters, the wings Gibeing withdrawn within the section by simply turning Vthe screw o in a reverse direction, when the cone E will be brought in contact with the inner ends of said wings, forcing the wings inward'as they turn on the pins e.

To supply water to the cuttin g-surfaces asv the drill revolves, the water is admitted through the pipe L, passes into the section H through the channels i i", (lubricating, at the same time, the screw on the stem 0,) into the coupling F, throughthe channels i i therein,into the tubular stem G, and thence into the section B, to

the cutting-surfaces, through the slots into which said wings work, and also through the tubular stem G,'through the perforations h, and thence through the openings in the upper cone, and through the hollow stem f, through the lower cone, and through the perforations c in the concave under cutting-surface, so that the cutting-surfaces of the wings and ofthe water.

Having thus described-the construction and operation of my adjustable expanding bit or "drill, what I claim as new, and desire to secure by Letters Patent, is-

l. A rock drill orbit constructed with-cutting-wings J, for enlarging the diameter of the bore, operated by adjustable cones D E, substantially as shown and described.

2. In a rock drill or bit, the combination o'f a nut, I, adjusting-screw-o, tubular stem G,

and cones D E with hinged cutting-Wings, sub- G, tubular nut I, and perforated base A, formsta'utially as and for the purpose described. ing' a. conduit for supplying Water to the out- 3. The combination, With the screw o and tingsurfdoes, substantially as speoied. stem Gr, of the coupling Z, substantially as and M. C, BULLOUK. for the purpose described. Witnesses:

4. In a rook drill or bit, the combination of H. L. WATTENBERG, the connected cones, recessed centrally, stem GEO. M. PLYMPTON. 

